Compound words are frequently seen in Sanskrit Vedanta and Upanishad texts. These are condensed sentences, nay entire paragraphs of subtle wisdom.

2.1.4 सह सुपा । With a word ending in a case-affix.
In this sutra the word अय is implicit, so it consists of three words, सुप् सह सुपा ।
-सह सुप् समस्यते समर्थेन a case-inflected word may be compounded with a word with which it is connected in sense. To put it another way, a join of two words that are somehow meaningfully related.
-सुपा सह समस्यते a case-inflected word is compounded with another sup-inflected word, i.e. compounding a tinganta/subanta pada with a subantam padam.
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4 Types of VisheshaSamasa = AvyayiBhava TatPurusha Bahuvrihi Dvandva

The VisheshaSamasa compound word has the four major types.
• I. TatPurusha, i.e. ThatBeing
• II. Bahuvrihi, i.e. ManyTypes/Indeterminate
• III. Dvandva, i.e. Noun word joins having equal or similar importance
• IV. AvyayiBhava, i.e. that which is an Indeclinable
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Concise discussion of Sanskrit Grammar Samasa = Compound Words. Gives relevant Ashtadhyayi Sutras.